1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Procedures for interfacing to the RTAS on CHRP machines. 5 * 6 * Peter Bergner, IBM March 2001. 7 * Copyright (C) 2001 IBM. 8 */ 9 10 #include <stdarg.h> 11 #include <linux/kernel.h> 12 #include <linux/types.h> 13 #include <linux/spinlock.h> 14 #include <linux/export.h> 15 #include <linux/init.h> 16 #include <linux/capability.h> 17 #include <linux/delay.h> 18 #include <linux/cpu.h> 19 #include <linux/sched.h> 20 #include <linux/smp.h> 21 #include <linux/completion.h> 22 #include <linux/cpumask.h> 23 #include <linux/memblock.h> 24 #include <linux/slab.h> 25 #include <linux/reboot.h> 26 #include <linux/syscalls.h> 27 28 #include <asm/prom.h> 29 #include <asm/rtas.h> 30 #include <asm/hvcall.h> 31 #include <asm/machdep.h> 32 #include <asm/firmware.h> 33 #include <asm/page.h> 34 #include <asm/param.h> 35 #include <asm/delay.h> 36 #include <linux/uaccess.h> 37 #include <asm/udbg.h> 38 #include <asm/syscalls.h> 39 #include <asm/smp.h> 40 #include <linux/atomic.h> 41 #include <asm/time.h> 42 #include <asm/mmu.h> 43 #include <asm/topology.h> 44 #include <asm/paca.h> 45 46 /* This is here deliberately so it's only used in this file */ 47 void enter_rtas(unsigned long); 48 49 struct rtas_t rtas = { 50 .lock = __ARCH_SPIN_LOCK_UNLOCKED 51 }; 52 EXPORT_SYMBOL(rtas); 53 54 DEFINE_SPINLOCK(rtas_data_buf_lock); 55 EXPORT_SYMBOL(rtas_data_buf_lock); 56 57 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned; 58 EXPORT_SYMBOL(rtas_data_buf); 59 60 unsigned long rtas_rmo_buf; 61 62 /* 63 * If non-NULL, this gets called when the kernel terminates. 64 * This is done like this so rtas_flash can be a module. 65 */ 66 void (*rtas_flash_term_hook)(int); 67 EXPORT_SYMBOL(rtas_flash_term_hook); 68 69 /* RTAS use home made raw locking instead of spin_lock_irqsave 70 * because those can be called from within really nasty contexts 71 * such as having the timebase stopped which would lockup with 72 * normal locks and spinlock debugging enabled 73 */ 74 static unsigned long lock_rtas(void) 75 { 76 unsigned long flags; 77 78 local_irq_save(flags); 79 preempt_disable(); 80 arch_spin_lock(&rtas.lock); 81 return flags; 82 } 83 84 static void unlock_rtas(unsigned long flags) 85 { 86 arch_spin_unlock(&rtas.lock); 87 local_irq_restore(flags); 88 preempt_enable(); 89 } 90 91 /* 92 * call_rtas_display_status and call_rtas_display_status_delay 93 * are designed only for very early low-level debugging, which 94 * is why the token is hard-coded to 10. 95 */ 96 static void call_rtas_display_status(unsigned char c) 97 { 98 unsigned long s; 99 100 if (!rtas.base) 101 return; 102 103 s = lock_rtas(); 104 rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c); 105 unlock_rtas(s); 106 } 107 108 static void call_rtas_display_status_delay(char c) 109 { 110 static int pending_newline = 0; /* did last write end with unprinted newline? */ 111 static int width = 16; 112 113 if (c == '\n') { 114 while (width-- > 0) 115 call_rtas_display_status(' '); 116 width = 16; 117 mdelay(500); 118 pending_newline = 1; 119 } else { 120 if (pending_newline) { 121 call_rtas_display_status('\r'); 122 call_rtas_display_status('\n'); 123 } 124 pending_newline = 0; 125 if (width--) { 126 call_rtas_display_status(c); 127 udelay(10000); 128 } 129 } 130 } 131 132 void __init udbg_init_rtas_panel(void) 133 { 134 udbg_putc = call_rtas_display_status_delay; 135 } 136 137 #ifdef CONFIG_UDBG_RTAS_CONSOLE 138 139 /* If you think you're dying before early_init_dt_scan_rtas() does its 140 * work, you can hard code the token values for your firmware here and 141 * hardcode rtas.base/entry etc. 142 */ 143 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE; 144 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE; 145 146 static void udbg_rtascon_putc(char c) 147 { 148 int tries; 149 150 if (!rtas.base) 151 return; 152 153 /* Add CRs before LFs */ 154 if (c == '\n') 155 udbg_rtascon_putc('\r'); 156 157 /* if there is more than one character to be displayed, wait a bit */ 158 for (tries = 0; tries < 16; tries++) { 159 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0) 160 break; 161 udelay(1000); 162 } 163 } 164 165 static int udbg_rtascon_getc_poll(void) 166 { 167 int c; 168 169 if (!rtas.base) 170 return -1; 171 172 if (rtas_call(rtas_getchar_token, 0, 2, &c)) 173 return -1; 174 175 return c; 176 } 177 178 static int udbg_rtascon_getc(void) 179 { 180 int c; 181 182 while ((c = udbg_rtascon_getc_poll()) == -1) 183 ; 184 185 return c; 186 } 187 188 189 void __init udbg_init_rtas_console(void) 190 { 191 udbg_putc = udbg_rtascon_putc; 192 udbg_getc = udbg_rtascon_getc; 193 udbg_getc_poll = udbg_rtascon_getc_poll; 194 } 195 #endif /* CONFIG_UDBG_RTAS_CONSOLE */ 196 197 void rtas_progress(char *s, unsigned short hex) 198 { 199 struct device_node *root; 200 int width; 201 const __be32 *p; 202 char *os; 203 static int display_character, set_indicator; 204 static int display_width, display_lines, form_feed; 205 static const int *row_width; 206 static DEFINE_SPINLOCK(progress_lock); 207 static int current_line; 208 static int pending_newline = 0; /* did last write end with unprinted newline? */ 209 210 if (!rtas.base) 211 return; 212 213 if (display_width == 0) { 214 display_width = 0x10; 215 if ((root = of_find_node_by_path("/rtas"))) { 216 if ((p = of_get_property(root, 217 "ibm,display-line-length", NULL))) 218 display_width = be32_to_cpu(*p); 219 if ((p = of_get_property(root, 220 "ibm,form-feed", NULL))) 221 form_feed = be32_to_cpu(*p); 222 if ((p = of_get_property(root, 223 "ibm,display-number-of-lines", NULL))) 224 display_lines = be32_to_cpu(*p); 225 row_width = of_get_property(root, 226 "ibm,display-truncation-length", NULL); 227 of_node_put(root); 228 } 229 display_character = rtas_token("display-character"); 230 set_indicator = rtas_token("set-indicator"); 231 } 232 233 if (display_character == RTAS_UNKNOWN_SERVICE) { 234 /* use hex display if available */ 235 if (set_indicator != RTAS_UNKNOWN_SERVICE) 236 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex); 237 return; 238 } 239 240 spin_lock(&progress_lock); 241 242 /* 243 * Last write ended with newline, but we didn't print it since 244 * it would just clear the bottom line of output. Print it now 245 * instead. 246 * 247 * If no newline is pending and form feed is supported, clear the 248 * display with a form feed; otherwise, print a CR to start output 249 * at the beginning of the line. 250 */ 251 if (pending_newline) { 252 rtas_call(display_character, 1, 1, NULL, '\r'); 253 rtas_call(display_character, 1, 1, NULL, '\n'); 254 pending_newline = 0; 255 } else { 256 current_line = 0; 257 if (form_feed) 258 rtas_call(display_character, 1, 1, NULL, 259 (char)form_feed); 260 else 261 rtas_call(display_character, 1, 1, NULL, '\r'); 262 } 263 264 if (row_width) 265 width = row_width[current_line]; 266 else 267 width = display_width; 268 os = s; 269 while (*os) { 270 if (*os == '\n' || *os == '\r') { 271 /* If newline is the last character, save it 272 * until next call to avoid bumping up the 273 * display output. 274 */ 275 if (*os == '\n' && !os[1]) { 276 pending_newline = 1; 277 current_line++; 278 if (current_line > display_lines-1) 279 current_line = display_lines-1; 280 spin_unlock(&progress_lock); 281 return; 282 } 283 284 /* RTAS wants CR-LF, not just LF */ 285 286 if (*os == '\n') { 287 rtas_call(display_character, 1, 1, NULL, '\r'); 288 rtas_call(display_character, 1, 1, NULL, '\n'); 289 } else { 290 /* CR might be used to re-draw a line, so we'll 291 * leave it alone and not add LF. 292 */ 293 rtas_call(display_character, 1, 1, NULL, *os); 294 } 295 296 if (row_width) 297 width = row_width[current_line]; 298 else 299 width = display_width; 300 } else { 301 width--; 302 rtas_call(display_character, 1, 1, NULL, *os); 303 } 304 305 os++; 306 307 /* if we overwrite the screen length */ 308 if (width <= 0) 309 while ((*os != 0) && (*os != '\n') && (*os != '\r')) 310 os++; 311 } 312 313 spin_unlock(&progress_lock); 314 } 315 EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */ 316 317 int rtas_token(const char *service) 318 { 319 const __be32 *tokp; 320 if (rtas.dev == NULL) 321 return RTAS_UNKNOWN_SERVICE; 322 tokp = of_get_property(rtas.dev, service, NULL); 323 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE; 324 } 325 EXPORT_SYMBOL(rtas_token); 326 327 int rtas_service_present(const char *service) 328 { 329 return rtas_token(service) != RTAS_UNKNOWN_SERVICE; 330 } 331 EXPORT_SYMBOL(rtas_service_present); 332 333 #ifdef CONFIG_RTAS_ERROR_LOGGING 334 /* 335 * Return the firmware-specified size of the error log buffer 336 * for all rtas calls that require an error buffer argument. 337 * This includes 'check-exception' and 'rtas-last-error'. 338 */ 339 int rtas_get_error_log_max(void) 340 { 341 static int rtas_error_log_max; 342 if (rtas_error_log_max) 343 return rtas_error_log_max; 344 345 rtas_error_log_max = rtas_token ("rtas-error-log-max"); 346 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) || 347 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) { 348 printk (KERN_WARNING "RTAS: bad log buffer size %d\n", 349 rtas_error_log_max); 350 rtas_error_log_max = RTAS_ERROR_LOG_MAX; 351 } 352 return rtas_error_log_max; 353 } 354 EXPORT_SYMBOL(rtas_get_error_log_max); 355 356 357 static char rtas_err_buf[RTAS_ERROR_LOG_MAX]; 358 static int rtas_last_error_token; 359 360 /** Return a copy of the detailed error text associated with the 361 * most recent failed call to rtas. Because the error text 362 * might go stale if there are any other intervening rtas calls, 363 * this routine must be called atomically with whatever produced 364 * the error (i.e. with rtas.lock still held from the previous call). 365 */ 366 static char *__fetch_rtas_last_error(char *altbuf) 367 { 368 struct rtas_args err_args, save_args; 369 u32 bufsz; 370 char *buf = NULL; 371 372 if (rtas_last_error_token == -1) 373 return NULL; 374 375 bufsz = rtas_get_error_log_max(); 376 377 err_args.token = cpu_to_be32(rtas_last_error_token); 378 err_args.nargs = cpu_to_be32(2); 379 err_args.nret = cpu_to_be32(1); 380 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf)); 381 err_args.args[1] = cpu_to_be32(bufsz); 382 err_args.args[2] = 0; 383 384 save_args = rtas.args; 385 rtas.args = err_args; 386 387 enter_rtas(__pa(&rtas.args)); 388 389 err_args = rtas.args; 390 rtas.args = save_args; 391 392 /* Log the error in the unlikely case that there was one. */ 393 if (unlikely(err_args.args[2] == 0)) { 394 if (altbuf) { 395 buf = altbuf; 396 } else { 397 buf = rtas_err_buf; 398 if (slab_is_available()) 399 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC); 400 } 401 if (buf) 402 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX); 403 } 404 405 return buf; 406 } 407 408 #define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL) 409 410 #else /* CONFIG_RTAS_ERROR_LOGGING */ 411 #define __fetch_rtas_last_error(x) NULL 412 #define get_errorlog_buffer() NULL 413 #endif 414 415 416 static void 417 va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, 418 va_list list) 419 { 420 int i; 421 422 args->token = cpu_to_be32(token); 423 args->nargs = cpu_to_be32(nargs); 424 args->nret = cpu_to_be32(nret); 425 args->rets = &(args->args[nargs]); 426 427 for (i = 0; i < nargs; ++i) 428 args->args[i] = cpu_to_be32(va_arg(list, __u32)); 429 430 for (i = 0; i < nret; ++i) 431 args->rets[i] = 0; 432 433 enter_rtas(__pa(args)); 434 } 435 436 void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...) 437 { 438 va_list list; 439 440 va_start(list, nret); 441 va_rtas_call_unlocked(args, token, nargs, nret, list); 442 va_end(list); 443 } 444 445 int rtas_call(int token, int nargs, int nret, int *outputs, ...) 446 { 447 va_list list; 448 int i; 449 unsigned long s; 450 struct rtas_args *rtas_args; 451 char *buff_copy = NULL; 452 int ret; 453 454 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) 455 return -1; 456 457 s = lock_rtas(); 458 459 /* We use the global rtas args buffer */ 460 rtas_args = &rtas.args; 461 462 va_start(list, outputs); 463 va_rtas_call_unlocked(rtas_args, token, nargs, nret, list); 464 va_end(list); 465 466 /* A -1 return code indicates that the last command couldn't 467 be completed due to a hardware error. */ 468 if (be32_to_cpu(rtas_args->rets[0]) == -1) 469 buff_copy = __fetch_rtas_last_error(NULL); 470 471 if (nret > 1 && outputs != NULL) 472 for (i = 0; i < nret-1; ++i) 473 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]); 474 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0; 475 476 unlock_rtas(s); 477 478 if (buff_copy) { 479 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); 480 if (slab_is_available()) 481 kfree(buff_copy); 482 } 483 return ret; 484 } 485 EXPORT_SYMBOL(rtas_call); 486 487 /* For RTAS_BUSY (-2), delay for 1 millisecond. For an extended busy status 488 * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds. 489 */ 490 unsigned int rtas_busy_delay_time(int status) 491 { 492 int order; 493 unsigned int ms = 0; 494 495 if (status == RTAS_BUSY) { 496 ms = 1; 497 } else if (status >= RTAS_EXTENDED_DELAY_MIN && 498 status <= RTAS_EXTENDED_DELAY_MAX) { 499 order = status - RTAS_EXTENDED_DELAY_MIN; 500 for (ms = 1; order > 0; order--) 501 ms *= 10; 502 } 503 504 return ms; 505 } 506 EXPORT_SYMBOL(rtas_busy_delay_time); 507 508 /* For an RTAS busy status code, perform the hinted delay. */ 509 unsigned int rtas_busy_delay(int status) 510 { 511 unsigned int ms; 512 513 might_sleep(); 514 ms = rtas_busy_delay_time(status); 515 if (ms && need_resched()) 516 msleep(ms); 517 518 return ms; 519 } 520 EXPORT_SYMBOL(rtas_busy_delay); 521 522 static int rtas_error_rc(int rtas_rc) 523 { 524 int rc; 525 526 switch (rtas_rc) { 527 case -1: /* Hardware Error */ 528 rc = -EIO; 529 break; 530 case -3: /* Bad indicator/domain/etc */ 531 rc = -EINVAL; 532 break; 533 case -9000: /* Isolation error */ 534 rc = -EFAULT; 535 break; 536 case -9001: /* Outstanding TCE/PTE */ 537 rc = -EEXIST; 538 break; 539 case -9002: /* No usable slot */ 540 rc = -ENODEV; 541 break; 542 default: 543 printk(KERN_ERR "%s: unexpected RTAS error %d\n", 544 __func__, rtas_rc); 545 rc = -ERANGE; 546 break; 547 } 548 return rc; 549 } 550 551 int rtas_get_power_level(int powerdomain, int *level) 552 { 553 int token = rtas_token("get-power-level"); 554 int rc; 555 556 if (token == RTAS_UNKNOWN_SERVICE) 557 return -ENOENT; 558 559 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY) 560 udelay(1); 561 562 if (rc < 0) 563 return rtas_error_rc(rc); 564 return rc; 565 } 566 EXPORT_SYMBOL(rtas_get_power_level); 567 568 int rtas_set_power_level(int powerdomain, int level, int *setlevel) 569 { 570 int token = rtas_token("set-power-level"); 571 int rc; 572 573 if (token == RTAS_UNKNOWN_SERVICE) 574 return -ENOENT; 575 576 do { 577 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level); 578 } while (rtas_busy_delay(rc)); 579 580 if (rc < 0) 581 return rtas_error_rc(rc); 582 return rc; 583 } 584 EXPORT_SYMBOL(rtas_set_power_level); 585 586 int rtas_get_sensor(int sensor, int index, int *state) 587 { 588 int token = rtas_token("get-sensor-state"); 589 int rc; 590 591 if (token == RTAS_UNKNOWN_SERVICE) 592 return -ENOENT; 593 594 do { 595 rc = rtas_call(token, 2, 2, state, sensor, index); 596 } while (rtas_busy_delay(rc)); 597 598 if (rc < 0) 599 return rtas_error_rc(rc); 600 return rc; 601 } 602 EXPORT_SYMBOL(rtas_get_sensor); 603 604 int rtas_get_sensor_fast(int sensor, int index, int *state) 605 { 606 int token = rtas_token("get-sensor-state"); 607 int rc; 608 609 if (token == RTAS_UNKNOWN_SERVICE) 610 return -ENOENT; 611 612 rc = rtas_call(token, 2, 2, state, sensor, index); 613 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && 614 rc <= RTAS_EXTENDED_DELAY_MAX)); 615 616 if (rc < 0) 617 return rtas_error_rc(rc); 618 return rc; 619 } 620 621 bool rtas_indicator_present(int token, int *maxindex) 622 { 623 int proplen, count, i; 624 const struct indicator_elem { 625 __be32 token; 626 __be32 maxindex; 627 } *indicators; 628 629 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen); 630 if (!indicators) 631 return false; 632 633 count = proplen / sizeof(struct indicator_elem); 634 635 for (i = 0; i < count; i++) { 636 if (__be32_to_cpu(indicators[i].token) != token) 637 continue; 638 if (maxindex) 639 *maxindex = __be32_to_cpu(indicators[i].maxindex); 640 return true; 641 } 642 643 return false; 644 } 645 EXPORT_SYMBOL(rtas_indicator_present); 646 647 int rtas_set_indicator(int indicator, int index, int new_value) 648 { 649 int token = rtas_token("set-indicator"); 650 int rc; 651 652 if (token == RTAS_UNKNOWN_SERVICE) 653 return -ENOENT; 654 655 do { 656 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); 657 } while (rtas_busy_delay(rc)); 658 659 if (rc < 0) 660 return rtas_error_rc(rc); 661 return rc; 662 } 663 EXPORT_SYMBOL(rtas_set_indicator); 664 665 /* 666 * Ignoring RTAS extended delay 667 */ 668 int rtas_set_indicator_fast(int indicator, int index, int new_value) 669 { 670 int rc; 671 int token = rtas_token("set-indicator"); 672 673 if (token == RTAS_UNKNOWN_SERVICE) 674 return -ENOENT; 675 676 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); 677 678 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && 679 rc <= RTAS_EXTENDED_DELAY_MAX)); 680 681 if (rc < 0) 682 return rtas_error_rc(rc); 683 684 return rc; 685 } 686 687 /** 688 * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR. 689 * 690 * @fw_status: RTAS call status will be placed here if not NULL. 691 * 692 * rtas_ibm_suspend_me() should be called only on a CPU which has 693 * received H_CONTINUE from the H_JOIN hcall. All other active CPUs 694 * should be waiting to return from H_JOIN. 695 * 696 * rtas_ibm_suspend_me() may suspend execution of the OS 697 * indefinitely. Callers should take appropriate measures upon return, such as 698 * resetting watchdog facilities. 699 * 700 * Callers may choose to retry this call if @fw_status is 701 * %RTAS_THREADS_ACTIVE. 702 * 703 * Return: 704 * 0 - The partition has resumed from suspend, possibly after 705 * migration to a different host. 706 * -ECANCELED - The operation was aborted. 707 * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call. 708 * -EBUSY - Some other condition prevented the suspend from succeeding. 709 * -EIO - Hardware/platform error. 710 */ 711 int rtas_ibm_suspend_me(int *fw_status) 712 { 713 int fwrc; 714 int ret; 715 716 fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL); 717 718 switch (fwrc) { 719 case 0: 720 ret = 0; 721 break; 722 case RTAS_SUSPEND_ABORTED: 723 ret = -ECANCELED; 724 break; 725 case RTAS_THREADS_ACTIVE: 726 ret = -EAGAIN; 727 break; 728 case RTAS_NOT_SUSPENDABLE: 729 case RTAS_OUTSTANDING_COPROC: 730 ret = -EBUSY; 731 break; 732 case -1: 733 default: 734 ret = -EIO; 735 break; 736 } 737 738 if (fw_status) 739 *fw_status = fwrc; 740 741 return ret; 742 } 743 744 void __noreturn rtas_restart(char *cmd) 745 { 746 if (rtas_flash_term_hook) 747 rtas_flash_term_hook(SYS_RESTART); 748 printk("RTAS system-reboot returned %d\n", 749 rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); 750 for (;;); 751 } 752 753 void rtas_power_off(void) 754 { 755 if (rtas_flash_term_hook) 756 rtas_flash_term_hook(SYS_POWER_OFF); 757 /* allow power on only with power button press */ 758 printk("RTAS power-off returned %d\n", 759 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 760 for (;;); 761 } 762 763 void __noreturn rtas_halt(void) 764 { 765 if (rtas_flash_term_hook) 766 rtas_flash_term_hook(SYS_HALT); 767 /* allow power on only with power button press */ 768 printk("RTAS power-off returned %d\n", 769 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 770 for (;;); 771 } 772 773 /* Must be in the RMO region, so we place it here */ 774 static char rtas_os_term_buf[2048]; 775 776 void rtas_os_term(char *str) 777 { 778 int status; 779 780 /* 781 * Firmware with the ibm,extended-os-term property is guaranteed 782 * to always return from an ibm,os-term call. Earlier versions without 783 * this property may terminate the partition which we want to avoid 784 * since it interferes with panic_timeout. 785 */ 786 if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") || 787 RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term")) 788 return; 789 790 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str); 791 792 do { 793 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL, 794 __pa(rtas_os_term_buf)); 795 } while (rtas_busy_delay(status)); 796 797 if (status != 0) 798 printk(KERN_EMERG "ibm,os-term call failed %d\n", status); 799 } 800 801 /** 802 * rtas_activate_firmware() - Activate a new version of firmware. 803 * 804 * Activate a new version of partition firmware. The OS must call this 805 * after resuming from a partition hibernation or migration in order 806 * to maintain the ability to perform live firmware updates. It's not 807 * catastrophic for this method to be absent or to fail; just log the 808 * condition in that case. 809 * 810 * Context: This function may sleep. 811 */ 812 void rtas_activate_firmware(void) 813 { 814 int token; 815 int fwrc; 816 817 token = rtas_token("ibm,activate-firmware"); 818 if (token == RTAS_UNKNOWN_SERVICE) { 819 pr_notice("ibm,activate-firmware method unavailable\n"); 820 return; 821 } 822 823 do { 824 fwrc = rtas_call(token, 0, 1, NULL); 825 } while (rtas_busy_delay(fwrc)); 826 827 if (fwrc) 828 pr_err("ibm,activate-firmware failed (%i)\n", fwrc); 829 } 830 831 #ifdef CONFIG_PPC_PSERIES 832 /** 833 * rtas_call_reentrant() - Used for reentrant rtas calls 834 * @token: Token for desired reentrant RTAS call 835 * @nargs: Number of Input Parameters 836 * @nret: Number of Output Parameters 837 * @outputs: Array of outputs 838 * @...: Inputs for desired RTAS call 839 * 840 * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off", 841 * "ibm,get-xive" and "ibm,set-xive" are currently reentrant. 842 * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but 843 * PACA one instead. 844 * 845 * Return: -1 on error, 846 * First output value of RTAS call if (nret > 0), 847 * 0 otherwise, 848 */ 849 int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...) 850 { 851 va_list list; 852 struct rtas_args *args; 853 unsigned long flags; 854 int i, ret = 0; 855 856 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) 857 return -1; 858 859 local_irq_save(flags); 860 preempt_disable(); 861 862 /* We use the per-cpu (PACA) rtas args buffer */ 863 args = local_paca->rtas_args_reentrant; 864 865 va_start(list, outputs); 866 va_rtas_call_unlocked(args, token, nargs, nret, list); 867 va_end(list); 868 869 if (nret > 1 && outputs) 870 for (i = 0; i < nret - 1; ++i) 871 outputs[i] = be32_to_cpu(args->rets[i + 1]); 872 873 if (nret > 0) 874 ret = be32_to_cpu(args->rets[0]); 875 876 local_irq_restore(flags); 877 preempt_enable(); 878 879 return ret; 880 } 881 882 #endif /* CONFIG_PPC_PSERIES */ 883 884 /** 885 * Find a specific pseries error log in an RTAS extended event log. 886 * @log: RTAS error/event log 887 * @section_id: two character section identifier 888 * 889 * Returns a pointer to the specified errorlog or NULL if not found. 890 */ 891 struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log, 892 uint16_t section_id) 893 { 894 struct rtas_ext_event_log_v6 *ext_log = 895 (struct rtas_ext_event_log_v6 *)log->buffer; 896 struct pseries_errorlog *sect; 897 unsigned char *p, *log_end; 898 uint32_t ext_log_length = rtas_error_extended_log_length(log); 899 uint8_t log_format = rtas_ext_event_log_format(ext_log); 900 uint32_t company_id = rtas_ext_event_company_id(ext_log); 901 902 /* Check that we understand the format */ 903 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) || 904 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG || 905 company_id != RTAS_V6EXT_COMPANY_ID_IBM) 906 return NULL; 907 908 log_end = log->buffer + ext_log_length; 909 p = ext_log->vendor_log; 910 911 while (p < log_end) { 912 sect = (struct pseries_errorlog *)p; 913 if (pseries_errorlog_id(sect) == section_id) 914 return sect; 915 p += pseries_errorlog_length(sect); 916 } 917 918 return NULL; 919 } 920 921 #ifdef CONFIG_PPC_RTAS_FILTER 922 923 /* 924 * The sys_rtas syscall, as originally designed, allows root to pass 925 * arbitrary physical addresses to RTAS calls. A number of RTAS calls 926 * can be abused to write to arbitrary memory and do other things that 927 * are potentially harmful to system integrity, and thus should only 928 * be used inside the kernel and not exposed to userspace. 929 * 930 * All known legitimate users of the sys_rtas syscall will only ever 931 * pass addresses that fall within the RMO buffer, and use a known 932 * subset of RTAS calls. 933 * 934 * Accordingly, we filter RTAS requests to check that the call is 935 * permitted, and that provided pointers fall within the RMO buffer. 936 * The rtas_filters list contains an entry for each permitted call, 937 * with the indexes of the parameters which are expected to contain 938 * addresses and sizes of buffers allocated inside the RMO buffer. 939 */ 940 struct rtas_filter { 941 const char *name; 942 int token; 943 /* Indexes into the args buffer, -1 if not used */ 944 int buf_idx1; 945 int size_idx1; 946 int buf_idx2; 947 int size_idx2; 948 949 int fixed_size; 950 }; 951 952 static struct rtas_filter rtas_filters[] __ro_after_init = { 953 { "ibm,activate-firmware", -1, -1, -1, -1, -1 }, 954 { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */ 955 { "display-character", -1, -1, -1, -1, -1 }, 956 { "ibm,display-message", -1, 0, -1, -1, -1 }, 957 { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 }, 958 { "ibm,close-errinjct", -1, -1, -1, -1, -1 }, 959 { "ibm,open-errinjct", -1, -1, -1, -1, -1 }, 960 { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 }, 961 { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 }, 962 { "ibm,get-indices", -1, 2, 3, -1, -1 }, 963 { "get-power-level", -1, -1, -1, -1, -1 }, 964 { "get-sensor-state", -1, -1, -1, -1, -1 }, 965 { "ibm,get-system-parameter", -1, 1, 2, -1, -1 }, 966 { "get-time-of-day", -1, -1, -1, -1, -1 }, 967 { "ibm,get-vpd", -1, 0, -1, 1, 2 }, 968 { "ibm,lpar-perftools", -1, 2, 3, -1, -1 }, 969 { "ibm,platform-dump", -1, 4, 5, -1, -1 }, 970 { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 }, 971 { "ibm,scan-log-dump", -1, 0, 1, -1, -1 }, 972 { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 }, 973 { "ibm,set-eeh-option", -1, -1, -1, -1, -1 }, 974 { "set-indicator", -1, -1, -1, -1, -1 }, 975 { "set-power-level", -1, -1, -1, -1, -1 }, 976 { "set-time-for-power-on", -1, -1, -1, -1, -1 }, 977 { "ibm,set-system-parameter", -1, 1, -1, -1, -1 }, 978 { "set-time-of-day", -1, -1, -1, -1, -1 }, 979 #ifdef CONFIG_CPU_BIG_ENDIAN 980 { "ibm,suspend-me", -1, -1, -1, -1, -1 }, 981 { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 }, 982 { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 }, 983 #endif 984 { "ibm,physical-attestation", -1, 0, 1, -1, -1 }, 985 }; 986 987 static bool in_rmo_buf(u32 base, u32 end) 988 { 989 return base >= rtas_rmo_buf && 990 base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) && 991 base <= end && 992 end >= rtas_rmo_buf && 993 end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE); 994 } 995 996 static bool block_rtas_call(int token, int nargs, 997 struct rtas_args *args) 998 { 999 int i; 1000 1001 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) { 1002 struct rtas_filter *f = &rtas_filters[i]; 1003 u32 base, size, end; 1004 1005 if (token != f->token) 1006 continue; 1007 1008 if (f->buf_idx1 != -1) { 1009 base = be32_to_cpu(args->args[f->buf_idx1]); 1010 if (f->size_idx1 != -1) 1011 size = be32_to_cpu(args->args[f->size_idx1]); 1012 else if (f->fixed_size) 1013 size = f->fixed_size; 1014 else 1015 size = 1; 1016 1017 end = base + size - 1; 1018 if (!in_rmo_buf(base, end)) 1019 goto err; 1020 } 1021 1022 if (f->buf_idx2 != -1) { 1023 base = be32_to_cpu(args->args[f->buf_idx2]); 1024 if (f->size_idx2 != -1) 1025 size = be32_to_cpu(args->args[f->size_idx2]); 1026 else if (f->fixed_size) 1027 size = f->fixed_size; 1028 else 1029 size = 1; 1030 end = base + size - 1; 1031 1032 /* 1033 * Special case for ibm,configure-connector where the 1034 * address can be 0 1035 */ 1036 if (!strcmp(f->name, "ibm,configure-connector") && 1037 base == 0) 1038 return false; 1039 1040 if (!in_rmo_buf(base, end)) 1041 goto err; 1042 } 1043 1044 return false; 1045 } 1046 1047 err: 1048 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n"); 1049 pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n", 1050 token, nargs, current->comm); 1051 return true; 1052 } 1053 1054 static void __init rtas_syscall_filter_init(void) 1055 { 1056 unsigned int i; 1057 1058 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) 1059 rtas_filters[i].token = rtas_token(rtas_filters[i].name); 1060 } 1061 1062 #else 1063 1064 static bool block_rtas_call(int token, int nargs, 1065 struct rtas_args *args) 1066 { 1067 return false; 1068 } 1069 1070 static void __init rtas_syscall_filter_init(void) 1071 { 1072 } 1073 1074 #endif /* CONFIG_PPC_RTAS_FILTER */ 1075 1076 /* We assume to be passed big endian arguments */ 1077 SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) 1078 { 1079 struct rtas_args args; 1080 unsigned long flags; 1081 char *buff_copy, *errbuf = NULL; 1082 int nargs, nret, token; 1083 1084 if (!capable(CAP_SYS_ADMIN)) 1085 return -EPERM; 1086 1087 if (!rtas.entry) 1088 return -EINVAL; 1089 1090 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) 1091 return -EFAULT; 1092 1093 nargs = be32_to_cpu(args.nargs); 1094 nret = be32_to_cpu(args.nret); 1095 token = be32_to_cpu(args.token); 1096 1097 if (nargs >= ARRAY_SIZE(args.args) 1098 || nret > ARRAY_SIZE(args.args) 1099 || nargs + nret > ARRAY_SIZE(args.args)) 1100 return -EINVAL; 1101 1102 /* Copy in args. */ 1103 if (copy_from_user(args.args, uargs->args, 1104 nargs * sizeof(rtas_arg_t)) != 0) 1105 return -EFAULT; 1106 1107 if (token == RTAS_UNKNOWN_SERVICE) 1108 return -EINVAL; 1109 1110 args.rets = &args.args[nargs]; 1111 memset(args.rets, 0, nret * sizeof(rtas_arg_t)); 1112 1113 if (block_rtas_call(token, nargs, &args)) 1114 return -EINVAL; 1115 1116 /* Need to handle ibm,suspend_me call specially */ 1117 if (token == rtas_token("ibm,suspend-me")) { 1118 1119 /* 1120 * rtas_ibm_suspend_me assumes the streamid handle is in cpu 1121 * endian, or at least the hcall within it requires it. 1122 */ 1123 int rc = 0; 1124 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32) 1125 | be32_to_cpu(args.args[1]); 1126 rc = rtas_syscall_dispatch_ibm_suspend_me(handle); 1127 if (rc == -EAGAIN) 1128 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE); 1129 else if (rc == -EIO) 1130 args.rets[0] = cpu_to_be32(-1); 1131 else if (rc) 1132 return rc; 1133 goto copy_return; 1134 } 1135 1136 buff_copy = get_errorlog_buffer(); 1137 1138 flags = lock_rtas(); 1139 1140 rtas.args = args; 1141 enter_rtas(__pa(&rtas.args)); 1142 args = rtas.args; 1143 1144 /* A -1 return code indicates that the last command couldn't 1145 be completed due to a hardware error. */ 1146 if (be32_to_cpu(args.rets[0]) == -1) 1147 errbuf = __fetch_rtas_last_error(buff_copy); 1148 1149 unlock_rtas(flags); 1150 1151 if (buff_copy) { 1152 if (errbuf) 1153 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0); 1154 kfree(buff_copy); 1155 } 1156 1157 copy_return: 1158 /* Copy out args. */ 1159 if (copy_to_user(uargs->args + nargs, 1160 args.args + nargs, 1161 nret * sizeof(rtas_arg_t)) != 0) 1162 return -EFAULT; 1163 1164 return 0; 1165 } 1166 1167 /* 1168 * Call early during boot, before mem init, to retrieve the RTAS 1169 * information from the device-tree and allocate the RMO buffer for userland 1170 * accesses. 1171 */ 1172 void __init rtas_initialize(void) 1173 { 1174 unsigned long rtas_region = RTAS_INSTANTIATE_MAX; 1175 u32 base, size, entry; 1176 int no_base, no_size, no_entry; 1177 1178 /* Get RTAS dev node and fill up our "rtas" structure with infos 1179 * about it. 1180 */ 1181 rtas.dev = of_find_node_by_name(NULL, "rtas"); 1182 if (!rtas.dev) 1183 return; 1184 1185 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base); 1186 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size); 1187 if (no_base || no_size) { 1188 of_node_put(rtas.dev); 1189 rtas.dev = NULL; 1190 return; 1191 } 1192 1193 rtas.base = base; 1194 rtas.size = size; 1195 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry); 1196 rtas.entry = no_entry ? rtas.base : entry; 1197 1198 /* If RTAS was found, allocate the RMO buffer for it and look for 1199 * the stop-self token if any 1200 */ 1201 #ifdef CONFIG_PPC64 1202 if (firmware_has_feature(FW_FEATURE_LPAR)) 1203 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX); 1204 #endif 1205 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE, 1206 0, rtas_region); 1207 if (!rtas_rmo_buf) 1208 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n", 1209 PAGE_SIZE, &rtas_region); 1210 1211 #ifdef CONFIG_RTAS_ERROR_LOGGING 1212 rtas_last_error_token = rtas_token("rtas-last-error"); 1213 #endif 1214 1215 rtas_syscall_filter_init(); 1216 } 1217 1218 int __init early_init_dt_scan_rtas(unsigned long node, 1219 const char *uname, int depth, void *data) 1220 { 1221 const u32 *basep, *entryp, *sizep; 1222 1223 if (depth != 1 || strcmp(uname, "rtas") != 0) 1224 return 0; 1225 1226 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL); 1227 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL); 1228 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL); 1229 1230 if (basep && entryp && sizep) { 1231 rtas.base = *basep; 1232 rtas.entry = *entryp; 1233 rtas.size = *sizep; 1234 } 1235 1236 #ifdef CONFIG_UDBG_RTAS_CONSOLE 1237 basep = of_get_flat_dt_prop(node, "put-term-char", NULL); 1238 if (basep) 1239 rtas_putchar_token = *basep; 1240 1241 basep = of_get_flat_dt_prop(node, "get-term-char", NULL); 1242 if (basep) 1243 rtas_getchar_token = *basep; 1244 1245 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE && 1246 rtas_getchar_token != RTAS_UNKNOWN_SERVICE) 1247 udbg_init_rtas_console(); 1248 1249 #endif 1250 1251 /* break now */ 1252 return 1; 1253 } 1254 1255 static arch_spinlock_t timebase_lock; 1256 static u64 timebase = 0; 1257 1258 void rtas_give_timebase(void) 1259 { 1260 unsigned long flags; 1261 1262 local_irq_save(flags); 1263 hard_irq_disable(); 1264 arch_spin_lock(&timebase_lock); 1265 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); 1266 timebase = get_tb(); 1267 arch_spin_unlock(&timebase_lock); 1268 1269 while (timebase) 1270 barrier(); 1271 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); 1272 local_irq_restore(flags); 1273 } 1274 1275 void rtas_take_timebase(void) 1276 { 1277 while (!timebase) 1278 barrier(); 1279 arch_spin_lock(&timebase_lock); 1280 set_tb(timebase >> 32, timebase & 0xffffffff); 1281 timebase = 0; 1282 arch_spin_unlock(&timebase_lock); 1283 } 1284